[Question] How do I create a custom mesh from a list/array of vertices?

[Mahmoud1205]

This is my Vertex struct

struct Vertex {
    glm::vec3 Position;
    glm::vec3 Normal;
    glm::vec2 TexCoords
}

I have a list of indices too

[jrouwe]

Here's an example:

JoltPhysics/Samples/Tests/Character/CharacterBaseTest.cpp

Lines 413 to 455 in 6370b0f

	// Create a half cylinder with caps for testing contact point limit
	{
	VertexList vertices;
	IndexedTriangleList triangles;
	// The half cylinder
	const int cPosSegments = 2;
	const int cAngleSegments = 512;
	const float cCylinderLength = 2.0f;
	for (int pos = 0; pos < cPosSegments; ++pos)
	for (int angle = 0; angle < cAngleSegments; ++angle)
	{
	uint32 start = (uint32)vertices.size();
	float radius = cCharacterRadiusStanding + 0.05f;
	float angle_rad = (-0.5f + float(angle) / cAngleSegments) * JPH_PI;
	float s = Sin(angle_rad);
	float c = Cos(angle_rad);
	float x = cCylinderLength * (-0.5f + float(pos) / (cPosSegments - 1));
	float y = angle == 0 || angle == cAngleSegments - 1? 0.5f : (1.0f - c) * radius;
	float z = s * radius;
	vertices.push_back(Float3(x, y, z));
	if (pos > 0 && angle > 0)
	{
	triangles.push_back(IndexedTriangle(start, start - 1, start - cAngleSegments));
	triangles.push_back(IndexedTriangle(start - 1, start - cAngleSegments - 1, start - cAngleSegments));
	}
	}
	// Add end caps
	uint32 end = cAngleSegments * (cPosSegments - 1);
	for (int angle = 0; angle < cAngleSegments - 1; ++angle)
	{
	triangles.push_back(IndexedTriangle(0, angle + 1, angle));
	triangles.push_back(IndexedTriangle(end, end + angle, end + angle + 1));
	}
	MeshShapeSettings mesh(std::move(vertices), std::move(triangles));
	mesh.SetEmbedded();
	BodyCreationSettings mesh_cylinder(&mesh, cHalfCylinderPosition, Quat::sIdentity(), EMotionType::Static, Layers::NON_MOVING);
	mBodyInterface->CreateAndAddBody(mesh_cylinder, EActivation::DontActivate);
	}

[Mahmoud1205]

Thank you, does the engine automatically optimize these (as in decreasing amount of vertices, if that even matters) or should I decrease the vertices of the collision body myself?

[jrouwe]

It only removes degenerate triangles, it doesn't do any further simplifications. Use another mesh simplification library if you want to simplify the mesh.